A Southborough youngster's idea to make fudge for her 98-year-old great-grandfather is landing her on the pitcher's mound at today's Red Sox game after she won a contest for her gooey good deed.

Kathryn Gowdy, 6, a kindergartner at Mary E. Finn Elementary School, will throw out the first pitch at Fenway Park tonight when the Red Sox take on Toronto.

Gowdy entered a contest celebrating the Ronald McDonald House of Boston's 30th anniversary and the 20th of the Providence house.

The HURRAH video contest challenged children ages 6 to 12 in eastern New England to do a "Heartfelt, Unforgettable, Rallying, Random Act of Happiness" and have a parent submit a video of it.

When Heather Gowdy described the contest to Kathryn and her brother, Alex, 8, Kathryn said she wanted to make fudge for her great-grandfather, George Sharpe, 98, of Portland, Maine.

"We bake for him sometimes, shortbread or fudge," said Heather Gowdy. "She decided that's what she wanted to do."

The video shows Kathryn stirring ingredients for penuche fudge on the stovetop with the help of Alex, a third-grader at Woodward Elementary School.

A few days later, the Gowdys traveled to New Hampshire to see family for Easter, where Kathryn gave the fudge to Sharpe. In the video, Sharpe tries the fudge and decrees it "delicious."

"He was really excited," Heather Gowdy said.

After submitting their video for the contest, Gowdy said the family never thought it would be picked as the winner. But it did, and Kathryn Gowdy has been practicing her pitching skills at home in preparation for tonight's game.

"I'm excited," Kathryn Gowdy said.

In addition to tomorrow night's festivities, including a tour of Fenway Park before the game, Gowdy will receive $500 in McDonald's Arch Cards good for food at the restaurant.

She will be joined at the game by her mother, her father, Ted, her brother and two uncles. Heather Gowdy said Fenway is too far for Sharpe to travel, but he plans to watch Kathryn's pitch on television.